The overall objective of the proposed research is to investigate how specific membrane proteins are synthesized and inserted into a biological membrane and how they interact, both functionally and structurally with the membrane. The synthesis and interaction of the membrane-associated coat protein of the fl bacteriophage is being studied as a model system. Attempts will be made to determine if the protein is first synthesized as a precursor molecule in vivo making use of various mutant bacterial and phage strains, various protease inhibitors and other immunological and biochemical techniques. The cellular location for the synthesis of the precursor will be determined and the role of the precursor in the insertion of the coat protein into the membrane investigated. Any protease(s) involved in the processing of the precursor in the insertion of the coat protein into the membrane investigated. Any protease(s) involved in the processing of the precursor will be identified, isolated and characterized. Attempts will be made to define an in vitro system which will synthesize the coat protein and insert it into defined phospholipid vesicles. The structure and orientation of the proteins in the vesicles will be examined using proteolytic enzymes, immunological and fingerprinting techniques. The mechanism by which membrane-associated coat protein affects the synthesis of certain phospholipids will be further investigated.